Combustion chamber



Feb. 16, 1954 JACKSON 2,669,090

COMBUSTION CHAMBER Filed Jan. 13, 1951 2 Sheets-Sheet l IN V EN TOR.

.Zfo'bcwi If Jackson Feb. 16, 1954 R J JACKSON 7 2,669,090

COMBUSTION CHAMBER Filed Jan. 15, 1951 2 Sheets-Sheet 2 -22? C Q Q Q 67\ H L l I INVENTOR. I .Zf'obeni rf zfczc/flsorz Patented Feb. 16, 1954 FICE :Lanova Cor rati sszls an ici -ia corporation lof-Dela'ware Application January 13 195 1,; Serial Nix-05,893

1 Claim. 1

"This invention relate's to combustion chambers, and has to do with-combustionchambers for use in driving gas turbinesand: ior analo ous purposes.

Combustion chambers for use inidriving gas turbines are known. The present combustion chambers are, in general, lacking in flexibility in respect to varying conditions encountered inthe use thereof and controlofthe (temperature of the gases delivered to theiturbine, and do not provide adequate cooling of the partsofthe combustion chamber to guard againstv injury ,by the -high --tem-peratures encountered, when operated --in ioaral1el witha second vsource of; combustion products which variesvwidelyinboth temperature and quantity; My invention is directed. to a .combnstion cham- 'berrwh-ich avoidsvtheiabovevnoted obj 'ens to the-present combustionchambers. -I lprovideu-a combustion chamber-i. .v-lflexibility is possible to ,SlliMl/MTi-Ous pp ating conditions encountered and adequate c moi the-parts is assured. In the cornbnstionph ber -o y invention combust on oc urs; madame ltubesnaced fnom.-.anienclss h ioe .18 o wh c a i dmit ed unde :Plifidllia fo S11 n r-tie icombustion-landior coolingthe hous t afiame tube as Well as jt he -cornb u whe e t itemrss ts e ith ease mess di c arge from'fih icom ns ienche b ima'r i'e d i an .l ra el com o ledli mbustib ha ter @9 m inv t ons aifi ar asiziisb o gusei ea. sys em ;.Q m; r s ns an ,a ,comsr prudrire deliyered tothe combustion chamber.

beyondthe primary combustion space. thereinso ;.a s-to avoid risk of extinguis'hment of the fianie 9Y-; en i e haust ea e wh e swim i o w t 'the ar ansemento h fiev tu e an associated ,,ele inents, ,constitutes an important .zi u ie m intentio Whil -th q mh stie .s embe o s-imyr nveni o is part cul r -s tab seinas ystem'of. thecharacter sta ,it is in l m te mm -nart wlan-u ean ma b EuSQ JflP a the Pu os in wh ch: ii su te f rth Q 'ie i and adi taa ro jm l invent o will. appear from .thedetaildescription.

.pl lithedr w nssz us a len t wise ent a eci ona lvie 2 Q the-comb s ion ham e v e bod ng my; in isna cmtai n rts be naprckenawayy Fig-ure ,2,is.,-a seetionallyiew taken substantially on ,line 2. 2 of Figure 1,' the adjacent portion of 1 the 1',1ousin being; -broken away EigureflB is a sectional yiewfsimilar to Figure 2 abut taken-on line 3-3 of Figure 1;

Figure is ayiew similar to Figure 1 but show- .ing a modified forrn ef-combustion chamber embo in m cinv n on; n

Figureb is a diagrammaticuyiew of a system em odyi g th QQm W iQ b am f 'i v on TI the-ior-rncf combustion chamber showniin ,Eigures 1 to 3,,inclusive, 'I provide a housing I of;-,generally cylindrical formhaving an end portionor estension gaff substantially frusto co'nical form, to theouterend of which is secured a bolt- -iving r-ingi Q-defining adischarge'opening Ill. ring Q isadapted for boltingjto a bolting flange l I ofan inlet-stack or conduit 12 of a gasturbineas will'appear more fully later.

Body portion fit'of'housing i is provided, at

its .otherjend byahead; IS. The parts of the assembly may be secured together in any suitable warmer, as vbyt'i z'e cl ns, b0 i g or th like a ,will {be i understood. ,An air supply conduit '20 ,opens intosectionrlfi, asshown. The headlQ is provided. with. an inwardly extendingboss 2 I in 'which issuitably mounted a fuel spray nozzle 22 .ofsuitableknowntype. Ignition means 23, which ,may be of ,suitablelgnown type, is provided adjacenttheinner end of nozzle 22 for igniting the A flame tube .2 3 is disposed within housing 1 and extends lengthwise thereof from th end at .Which the head is is located, which may be defined as the fuel supply end of the housing. The

flame tube 214 is of substantially conical shape and flares from thefuel supply and of the housfing toward the d ischa rge end thereof. This fianfle tube 24 comprises an inner section 25 and 45 an outer seet iontt. The inner section 25 extends outward from boss Zi as shown, and is provided with perforations Zt throughout its extent, of adequatetotal area to assure supply of air to the primary combustion space defined by sectiontfi lin amountto support rapid and substantially complete cornbnstionof the injected fuel. n

CYIiIlQXfiCgI CQQIlg tfl which is imperforate, surrqunds ec e fzt o ame u e d i sn ,lythere bo iai i uqui nd o as to v d a closure therewith, asshown. The outerend of 26 of flame tube 24, also providing a closure therewith, and the inner end of casing 30 fits snugly within ring H to which it may be welded or otherwise suitably secured. An air flow straightener 32, in the form of an annulus or ring, fits snugly about section 25 of flame tube 24, adjacent the inner end thereof, and extends therefrom outward radially beyond the casing 30. This straightener 32 (Figure 2) is provided with perforations 33 of adequate total area not to objectionably impede free flow of air from space 34, between head 19 and straightener 32, into the space 35 extending about flame tube section 25 between the latter and casing 30. It will be clear, from what has been said, that the space 34 is closed off from space 36 extending about casing 33 between the latter and section I6 of the housing 1.

A perforated annular air flow straightener 31 fits snugly about section 26 of the flame tube 24, adjacent the inner end thereof, and extends radially outward to the inner end of body section l3 of housing 1. An air supply conduit 38 opens into space 35, from which air flows through the straightener 31 (Figure 3) into space 39 between section 25 of the flame tube 24 and the surround ing wall of body section l3 of housing 1. The total area of perforations 31a of air flow straightener 31 is adequate to guard against objectionably impeding free flow of air therethrough into space 39. Section 26 of flame tube 24 defines a secondary combustion space extending outward from the primary combustion space within section 25. Section 26 is provided, for the major portion of its length, with perforations 43 the total area of which is adequate to assure free flow of air therethrough in sufiicient quantity to maintain the flame Within section 26 While also serving as a diluent, as circumstances may require, for cooling the hot products of combustion. The outer portion of section 26 of the flame tube 24 is provided with perforations 4| of greater diameter than the perforations 43, for admission to that portion of section 26 of cooling air. A conduit 42 opens into housing 1 outwardly beyond the primary combustion space within the flame tube 24. This conduit 42 may be connected to a suitable source of combustion gases. In the system of the character above referred to, the conduit 42 is connected to the exhaust of an internal combustion engine for delivering to housing 1 the exhaust gases from the engine for mixing with the combustion gases issuing from the flame tube 24. It is of importance that complete combustion of the fuel supplied to the flame tube be assured, in order that the volume, temperature and pressure of the combustion gases issuing therefrom be maintained at the optimum values for most efficient operation. It is important, therefore, that the conduit 42 be so disposed that the entering engine exhaust gases will not quench the flame or retard combustion in the primary combustion space. Preferably, the conduit opens into housing 1 adjacent the outer or outlet end of flame tube 24, between the latter and the discharge end of housing 1, as shown. That arrangement of the conduit 42 is also of importance in that it is conducive to flexibility of control of the temperature of the gases delivered to the gas turbine, as will appear more fully later.

The modified form of combustion chamber, shown in Figure 4, is similar to that shown in Figure 1, but is somewhat different in respect to structural features. It comprises the housing 43 having a cylindrical body 44 and an extension 45 to the discharge end of which is secured a rin 46 defining a discharge opening 41. The ring 46 is suitably secured, conveniently by bolting, to flange 41 of the inlet stack or conduit 48 of a gas turbine. A cylindrical section 50 is secured to the inner end of body section 44, conveniently by means of rings 5| and 52 on the adjacent ends of sections 44 and 50, respectively, bolted or otherwise suitably secured together. The end of section 50 remote from section 44 is closed by a head 53 provided with a boss 54 carrying a fuel injection nozzle 55 and ignition means 56. A flame tube 51, perforated and of conical shape, extends lengthwise within the housing 43 from boss 54 to extension 45, the outlet end of this tube fitting within housing 43 so as to form therewith a closure about the flame tube. The tube 51 is provided for a major portion of its length with perforations 58 and, at its outer portion, with perforations 59 of materially greater diameter than the perforations 58. As will be understood from what has been said, the tube 51 defines an inner primary combustion space and an outer secondary combustion space.

A perforated air flow straightener 6t fits about flame tube 51 a short distance from the inner end thereof and extends radially outward therefrom to the section 50, providing an inner perforated end wall therefor. An air supply conduit 61 opens into section 50 and a conduit 62 opens into extension 45 of housing 43 for supplying thereto combustion gases, such as the exhaust gases from an internal combustion engine.

In Figure 5 I have shown the combustion chamber, designated 65, of Figures 1 to 3, inclusive, embodied in a system of the character above referred to comprising a gas turbine T, a compressor C driven by turbine T and an internal combustion engine E. Atmospheric air enters the compressor C through conduit 66 and air under pressure is delivered from the compressor C through conduit 61 to intake manifold I of engine E. Air under pressure is also delivered from compressor C, through conduit 68, to the air supply conduits 20 and 38 of combustion chamber 65, each of the conduits 20 and 38 being provided with a control valve 69 of suitable known type. Fuel is supplied to the injector nozzle 22 of combustion chamber 65 through a conduit 10 controlled by a valve 1|. The exhaust manifold X of engine E is connected by a conduit 12 to the exhaust gas supply conduit 42 of combustion chamber 65, and the discharge end of combustion chamber 65 is connected to the intake stack or conduit [2 of turbine T, the exhaust from which is discharged through conduit 14.

Fuel and air are introduced into the flame tube in proper proportion to assure complete combustion of the fuel in the primary combustion space. In that connection, uniform distribution of the primary air is of importance and the air flow straightener 32 is of assistance in that respect. The primary air enters through the air supply conduit 20 and may be regulated in amount by the valve 69 therein, as will be understood. The secondary air enters through the air supply conduit 38 and flows through the air flow straightener 31 substantially lengthwise of the housing so as to be distributed substantially uniformly along the flame tube, this secondary air passing through the perforations 40 and 4| of the flame tube into the interior thereof for maintaining combustion. This secondary air serves to cool the housing and the flame tube, and also serves as a diluent of the combustion gases and to cool the latter as may be required. The combustion gases ejected from the flame tube mix with the engine exhaust gases entering the housing of the combustion chamber through the conduit 42, and the resultant gas mixture is delivered to the turbine T at appropriate temperature and pressure to assure most efficient operation thereof. The secondary air entering through supply conduit 38 also serves to maintain the proper volume or mass flow of gases to the turbine to assure maximum efficiency in operation of the latter.

When the engine is operating under light load, the exhaust gases delivered therefrom to the combustion chamber will be relatively cool. In such case the quantity of secondary air delivered to the combustion chamber will be reduced in amount sufiicient to assure that the gas mixture discharged from the combustion chamber to the turbine will be at the optimum operating temperature. As the operating load of the engine increases the temperature of the exhaust gases also increases with a corresponding reduction in the amount of heat which should be added to the combustion chamber. Accordingly, as the engine load increases the amount of secondary air supplied to the combustion chamber may be increased and the fuel supply decreased to maintain the optimum operating temperature of the ga mixture discharged from the combustion chamber while guarding against injury thereto by excessively high temperatures. When the engine is operating under full load conditions the temperature of the exhaust gases may be above the optimum operating temperature. In such cases the supply of fuel and primary air to the combustion chamber may be cut off and the amount of secondary air delivered to the combustion chamber may be increased sufilciently to assure adequate cooling of the combustion chamber, the secondary air then also serving to dilute the exhaust gases from the engine and to maintain the gas mixture delivered to the turbine at the optimum operating temperature. It will be seen that the combustion chamber of my invention is highly flexible to meet the varying conditions encountered in the operation of a system of the character referred to, and may be utilized either as a source of combustiongases, or as means for mixing air with the exhaust gases delivered from the internal combustion engine, as conditions may require for most efiicient operation of the system.

The operation of the modified form of combustion chamber shown in Figure 4 is, in general, similar to that of the combustion chamber of Figure 1. In Figure 4 the primary air and the secondary air are both supplied to the single conduit 6|, as will be understood. While the provision of two air supply conduits, one of primary air and the other for secondary air, as in'Figure 1, is conducive to increased flexibility of the combustion chamber, that is not essential to the broader aspects of my invention many of the benefits of which are realized in the combustion chamber shown in Figure 4. As will be understood, any suitable fuel supply and ignition means may be provided, the injection nozzle and the ignition means shown being by way of example only.

It will be understood that changes in detail may 7 be resorted to without departing from the field and scope of my invention, and I intend to include all such variations, as fall within the appended claim, in this application in which the preferred forms only of my invention have been disclosed.

I claim:

In a combustion chamber for use in driving a gas turbine, a substantially cylindrical housing having a discharge end for connection to a gas turbine and a fuel supply end, a substantially conical perforated flame tube within said housing extending lengthwise thereof having a fuel inlet end adjacent said fuel supply end and an open outletyend spaced from said discharge end, said tube comprising an inner section defining a primary combustion space and an outer section defining a secondary combustion space and spaced for substantially its full length from the surrounding wall of said housing defining therewith an unobstructed annular space about said tube decreasing uniformly in cross section toward the outlet end of said tube, the outlet end of said outer section fitting the interior of said housing providing therewith a closure about said tube, means for supplying fuel to said primary combustion space, a substantially cylindrical casing extending about said inner section of said tube with its outer end in interfittmg relation to the outer end of said inner section and the inner end of said outer section providing therewith closures thereabout, said casing defining with said inner section an unobstructed annular space about the latter uniformly decreasing in cross section toward said secondary combustion space, said casing being spaced from the surrounding wall of said housing and having its inner end spaced from said fuel supply end of said housing and closed to the space between said housing and casing, a perforated air flow straightener at the inner end of said casing fitting about said inner section of said tube, a second perforated air flow straightener fitting between said housing and said second section of said tube adjacent the inner end thereof, air supply conduits respectively opening into said housing between said fuel supply end thereof and said first flow straightener and between the inner end of said casing and said second flow straightener, and a conduit opening into said housing between the discharge end thereof and the outlet end of said tube for supplying to said housing exhaust gases from an internal combustion engine.

ROBERT J. JACKSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,159,758 Diedrich May 23, 1939 2,216,494 Kurtz et a1 Oct. 1, 1940 2,227,666 Noack Jan. 7, 1941 2,446,059 Peterson et a1 July 27, 1948 2,448,561 Way Sept. 7, 1948 2,457,157 King, Jr. Dec. 28, 1948 2,458,497 Bailey Jan. 11, 1949 2,525,206 Clarke Oct. 10, 1950 2,545,495 Sforzini Mar. 20, 1951 2,585,968 Schneider Feb. 19, 1952 2,605,611 Wosika Aug. 5, 1952 FOREIGN PATENTS Number Country Date 597,205 Great Britain Jan. 20, 1948 

